Keep talking, trust each other...and enjoy a regular tipple together: these are some of the marriage tips passed on by celebrities to Prince Harry and Meghan Markle.
Stars including celebrity chef Jamie Oliver, actor Michael Morpurgo and film-maker Baz Luhrmann have been sharing their secrets to a long and happy union with ITV News ahead of the royal wedding.
Romeo and Juliet director Lurhmann said a perfect marriage is a building conversation "that continues forever".
He said "It grows and things change, but you still somehow are having that connection that you had when you first met."
Broadcaster Dan Snow says they should "talk all the time, do things together and grow together. That, and drink a lot of gin."
His advice might contrast with that of singer Cheryl Baker of Bucks Fizz - now known as The Fizz - who says that time apart can be golden.
"Don't spend all you time with each other, spend as much time as you can apart," she advised.
Others were less certain about the recipe for success.
"I think you'd have to ask my wife, " said actor Morpurgo, adding: "I don't know that it's organisable."
But perhaps chef Oliver has the one sure-fire tip for success.
He told the royal couple the key to keeping a marriage was "Just don't go away, keep hanging around and never go."
- Special coverage of Harry and Meghan – The Royal Wedding will be broadcast on ITV from 9.25am on Saturday 19th May. For more on the wedding and other stories on the Royal Family, follow the ITV News Royals page on Facebook.